Butte, Montana, October 1891, and a hard winter approaches across the Rocky Mountains. The city is rich on copper mines and rampant with vice and debauchery among a hard-living crowd of immigrant Irish workers. Set in the American West of the 1890s, the novel tracks the dangerously forbidden affair between a torrid young balladeer and the wife of a devout and powerful mine captain.

Tom Rourke is a young poet and balladmaker of the town, but also a doper, a drinker, and a fearsome degenerate. Just as he feels his life is heading nowhere fast, Polly Gillespie arrives in town as the new bride of the extremely devout mine captain Long Anthony Harrington. A thunderbolt love affair takes spark between Tom and Polly and they strike out west on a stolen horse, moving through the bad-lands of Montana and Idaho, and briefly an idyll of wild romance perfects itself. But a posse of deranged Cornish gunsmen are soon in hot pursuit of the lovers, and closing in fast.